Evidence for s-channel single top quark production in $p\bar{p}$ collisions at sqrt(s) = 1.96 TeV
V.M. Abazov
,
G. Sajot
(1)
,
J. Stark
(1)
,
S. Greder
(2)
,
F. Miconi
(2)
,
I. Ripp-Baudot
(2)
,
G. Bernardi
(3)
,
D. Brown
(3)
,
Y. Enari
(3)
,
J. Lellouch
(3)
,
D. Li
(3)
,
L. Zivkovic
(3)
,
G. Grenier
(4)
,
T. Kurca
(4)
,
P. Lebrun
(4)
,
F. Badaud
(5)
,
Ph. Gris
(5)
,
M.-C. Cousinou
(6)
,
A. Duperrin
(6)
,
W. Geng
(6)
,
E. Kajfasz
(6)
,
S. Kermiche
(6)
,
E. Nagy
(6)
,
N. Osman
(6)
,
J.-F. Grivaz
(7)
,
T. Guillemin
(7)
,
M. Jaffré
(7)
,
P. Pétroff
(7)
1
LPSC -
Laboratoire de Physique Subatomique et de Cosmologie
2 IPHC - Institut Pluridisciplinaire Hubert Curien
3 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
4 IPNL - Institut de Physique Nucléaire de Lyon
5 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
6 CPPM - Centre de Physique des Particules de Marseille
7 LAL - Laboratoire de l'Accélérateur Linéaire
2 IPHC - Institut Pluridisciplinaire Hubert Curien
3 LPNHE - Laboratoire de Physique Nucléaire et de Hautes Énergies
4 IPNL - Institut de Physique Nucléaire de Lyon
5 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
6 CPPM - Centre de Physique des Particules de Marseille
7 LAL - Laboratoire de l'Accélérateur Linéaire
V.M. Abazov
- Function : Author
G. Bernardi
- Function : Author
- PersonId : 1374140
- ORCID : 0000-0002-2837-2442
- IdRef : 088561623
P. Lebrun
- Function : Author
- PersonId : 741027
- IdHAL : patrice-jean-marie-lebrun
- ORCID : 0000-0001-6115-5856
E. Kajfasz
- Function : Author
- PersonId : 742630
- IdHAL : eric-kajfasz
- ORCID : 0000-0002-8575-405X
- IdRef : 150389043
Abstract
We present measurements of the cross sections for the two main production modes of single top quarks in $p\bar{p}$ collisions at $\sqrt{s} = 1.96$\;TeV in the Run II data collected with the D0 detector at the Fermilab Tevatron Collider, corresponding to an integrated luminosity of 9.7\;fb$^{-1}$. The s-channel cross section is measured to be $\sigma({\ppbar}{\rargap}tb+X) = 1.10^{+0.33}_{-0.31}$\;pb with no assumptions on the value of the t-channel cross section. Similarly, the t-channel cross section is measured to be $\sigma({\ppbar}{\rargap}tqb+X) = 3.07^{+0.54}_{-0.49}$\;pb. We also measure the $s+t$ combined cross section as $\sigma({\ppbar}{\rargap}tb+X, tqb+X) = 4.11^{+0.60}_{-0.55}$\;pb and set a lower limit on the CKM matrix element $|V_{tb}| > 0.92 at 95% C.L., assuming $m_t=172.5$\;GeV. The probability to measure a cross section for the s channel at the observed value or higher in the absence of signal is $1.0\times 10^{-4}$, corresponding to a significance of 3.7 standard deviations.